Dundon 991 (and 997) GT3/RS Tips
09-04-2016, 03:41 AM
#16
Originally Posted by Jamie@dundonmotorsports
Can't restrict the flow, if you need less volume, that's better done in other ways... So turn down only. We've designed a Laguna Seca muffler that would cut down sound levels a bunch, but isn't so nice hanging off the back of the car...
09-04-2016, 03:47 AM
#17
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It is , the message I was answering was asking for baffles or other adders to the the turn down tips. We're not planning on doing that, just turn down tips that are completely adjustable for orientation.
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Dundon Motorsports
Gig Harbor, WA
253-200-4454
jamie@dundonmotorsports.com
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Dundon Motorsports
Gig Harbor, WA
253-200-4454
jamie@dundonmotorsports.com
www.dundonmotorsports.com
Facebook.com/dundonmotorsports
Instagram @dundon_motorsports
09-04-2016, 04:13 AM
#18
Originally Posted by Jamie@dundonmotorsports
It is , the message I was answering was asking for baffles or other adders to the the turn down tips. We're not planning on doing that, just turn down tips that are completely adjustable for orientation.
09-04-2016, 03:51 PM
#20
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Seriously though, there is a scientific explanation on how the tips can help with wave expansion... We want to get some logs of the car for supporting data before we post up the dyno...
09-21-2016, 09:00 PM
#21
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Update:
We're working to get these out. About to put the stocking order in for parts to make all 4 varieties of the Black Coated Steel Tips, and Ti tips with heat exposed edges (to make the blue everyone likes).
We've also just finished the CAD drawings to get these done in Carbon Fiber. The carbon will be a bit more, but should be awesome!
We're still futzing with where to put our logo on them, should have that nailed down by next week (laser mark, water jet, weld on etc...) and we'll get a bit of a group buy going, will be nuts as there are 12 different kinds of tips to choose from...
We're working to get these out. About to put the stocking order in for parts to make all 4 varieties of the Black Coated Steel Tips, and Ti tips with heat exposed edges (to make the blue everyone likes).
We've also just finished the CAD drawings to get these done in Carbon Fiber. The carbon will be a bit more, but should be awesome!
We're still futzing with where to put our logo on them, should have that nailed down by next week (laser mark, water jet, weld on etc...) and we'll get a bit of a group buy going, will be nuts as there are 12 different kinds of tips to choose from...
09-21-2016, 11:34 PM
#23
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The full megaphone are a tad louder and "cleaner" to my ear at part to full throttle. The megaphone-slash, 4" straight and 4" slash all about the same as far as I can tell.
Over the winter we're working on a Dundon Center Muffler...
09-22-2016, 02:26 AM
#24
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Hi Jamie. Im watching this in anticipation :-).
Im going to write up my road review of the DMS headers on 991 GT3 shortly.
One thing I found interesting. When removing my OEM third muffler from stock headers the dealer found three of the studs (on the side of the muffler box) snapped.
For a few hours there everyone in the workshop was looking for the other 2-3 OEM centre mufflers they had taken off other 991 GT3 (for sharkwerks bypass) over the last 12 months. It looked like I could be in serious trouble as the fabrication shop they sent the muffler to to have repaired as a back up said it was not possible to replace the studs without cutting the muffler box open entirely!
A few hours later three used boxes were found - and guess what? Two of them also had broken studs! The thrid was a basically brand new unit taken off a car with 400 miles. Its the one they installed for me (no charge) but on closer inspection it too had a snapped studs - but the break was heigh enough that it still had all the thread they needed to bolt it on.
Jamie, have you come across this situation with clients? Obviously this is nothing to do with your product. My box was replaced with Sharkwerks at 2000 road miles then reinstalled in Feburay with the G engine and it saw another 4000 miles use including 6 track days - but the other boxes were all form cars that had seen much lower mileage (in one case only 400 miles!) and no track use!
Once the studs snap it seems there is no easy way to repair the box other than cut it open? To me this sounds like a flaw in the product design - essentially Porsche are giving us one use boxes!
The dealer claims they rarely remove the rear box on its own unless they do a bypass, with the engine swaps from PAG they unbolt at the CAT as the new engine comes with new headers and cat. They say its 100% likely removing the box will find snapped studs rendering the old box pretty much useless.
Id appreciate your view (or others) on this as I had not read about it and was not expecting it. Is there something I am missing here?
Luckily in the end I got my DMS installed with a basically brand new box but it was touch and go and the dealer now has 3 failed boxes in reserve (i.e. useless the y can be repaired).
Here is a picture of one of the snapped studs (other side has two snapped studs).
Im going to write up my road review of the DMS headers on 991 GT3 shortly.
One thing I found interesting. When removing my OEM third muffler from stock headers the dealer found three of the studs (on the side of the muffler box) snapped.
For a few hours there everyone in the workshop was looking for the other 2-3 OEM centre mufflers they had taken off other 991 GT3 (for sharkwerks bypass) over the last 12 months. It looked like I could be in serious trouble as the fabrication shop they sent the muffler to to have repaired as a back up said it was not possible to replace the studs without cutting the muffler box open entirely!
A few hours later three used boxes were found - and guess what? Two of them also had broken studs! The thrid was a basically brand new unit taken off a car with 400 miles. Its the one they installed for me (no charge) but on closer inspection it too had a snapped studs - but the break was heigh enough that it still had all the thread they needed to bolt it on.
Jamie, have you come across this situation with clients? Obviously this is nothing to do with your product. My box was replaced with Sharkwerks at 2000 road miles then reinstalled in Feburay with the G engine and it saw another 4000 miles use including 6 track days - but the other boxes were all form cars that had seen much lower mileage (in one case only 400 miles!) and no track use!
Once the studs snap it seems there is no easy way to repair the box other than cut it open? To me this sounds like a flaw in the product design - essentially Porsche are giving us one use boxes!
The dealer claims they rarely remove the rear box on its own unless they do a bypass, with the engine swaps from PAG they unbolt at the CAT as the new engine comes with new headers and cat. They say its 100% likely removing the box will find snapped studs rendering the old box pretty much useless.
Id appreciate your view (or others) on this as I had not read about it and was not expecting it. Is there something I am missing here?
Luckily in the end I got my DMS installed with a basically brand new box but it was touch and go and the dealer now has 3 failed boxes in reserve (i.e. useless the y can be repaired).
Here is a picture of one of the snapped studs (other side has two snapped studs).
Last edited by Macca; 09-22-2016 at 03:42 AM.
09-22-2016, 02:47 AM
#25
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Hi Jamie. Im watching this in anticipation :-).
Im going to write up my road review of the DMS headers on 991 GT3 shortly.
One thing I found interesting. When removing my OEM third muffler from stock headers the dealer found two of the studs (on the side of the muffler box) snapped.
For a few hours there everyone in the workshop was looking for the other 2-3 OEM centre mufflers they had taken off other 991 GT3 (for sharkwerks bypass) over the last 12 months. It looked like I could be in serious trouble as the fabrication shop they sent the muffler to to have repaired as a back up said it was not possible to replace the studs without cutting the thrid muffler box open entirely!
A few hours later three used boxes were found - and guess what? Two of them also had broken studs! The thrid was a basically brand new unit taken off a car with 400 miles. Its the one they installed for me (no charge) but on closer inspection it too had a snapped stuff but the break was height enough that it still had all the thread they needed to bolt it on.
Jamie, have you come across this situation with clients? Obviously this is nothing to do with your product. My box was replaced with Sharkwerks at 2000 road miles then reinstalled in Feburay with the G engine and it saw another 4000 miles use including 6 track days - but the other boxes were all form cars that had seen much lower mileage (in one case only 400 miles!) and no track use!
Once the studs snap it seems there is no easy way to repair the box other than cut it open? To me this sounds like a flaw in the product design - essentially Porsche are giving us one use boxes!
The dealer claims they rarely remove the rear box on its own unless they do a bypass, with the engine swaps from PAG they unbolt at the CAT as the new engine comes with new headers and cat. They say its 100% likely removing the box will find snapped studs rendering the old box pretty much useless.
Id appreciate your view (or others) on this as I had not read about it and was not expecting it. Is there something I am missing here?
Luckily in the end I got my DMS installed with a basically brand new box but it was touch and go and the dealer now has 3 failed boxes in reserve (i.e. useless unless repaired).
Here is a picture of one of the snapped studs (other side has two snapped studs).
Im going to write up my road review of the DMS headers on 991 GT3 shortly.
One thing I found interesting. When removing my OEM third muffler from stock headers the dealer found two of the studs (on the side of the muffler box) snapped.
For a few hours there everyone in the workshop was looking for the other 2-3 OEM centre mufflers they had taken off other 991 GT3 (for sharkwerks bypass) over the last 12 months. It looked like I could be in serious trouble as the fabrication shop they sent the muffler to to have repaired as a back up said it was not possible to replace the studs without cutting the thrid muffler box open entirely!
A few hours later three used boxes were found - and guess what? Two of them also had broken studs! The thrid was a basically brand new unit taken off a car with 400 miles. Its the one they installed for me (no charge) but on closer inspection it too had a snapped stuff but the break was height enough that it still had all the thread they needed to bolt it on.
Jamie, have you come across this situation with clients? Obviously this is nothing to do with your product. My box was replaced with Sharkwerks at 2000 road miles then reinstalled in Feburay with the G engine and it saw another 4000 miles use including 6 track days - but the other boxes were all form cars that had seen much lower mileage (in one case only 400 miles!) and no track use!
Once the studs snap it seems there is no easy way to repair the box other than cut it open? To me this sounds like a flaw in the product design - essentially Porsche are giving us one use boxes!
The dealer claims they rarely remove the rear box on its own unless they do a bypass, with the engine swaps from PAG they unbolt at the CAT as the new engine comes with new headers and cat. They say its 100% likely removing the box will find snapped studs rendering the old box pretty much useless.
Id appreciate your view (or others) on this as I had not read about it and was not expecting it. Is there something I am missing here?
Luckily in the end I got my DMS installed with a basically brand new box but it was touch and go and the dealer now has 3 failed boxes in reserve (i.e. useless unless repaired).
Here is a picture of one of the snapped studs (other side has two snapped studs).
I'll forward this to Charles and see if we can work with Ehrin at Continental to get these other boxes resolved for you.
09-22-2016, 03:20 AM
#26
09-22-2016, 03:39 AM
#27
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Snapped studs are from over-tightening, possibly at the factory? We've seen it here and They can be fixed without cutting the muffler apart. Charles has fixed these studs on other mufflers successfully. If the shipping wasn't so expensive we'd happily take these off your dealers hands!
I'll forward this to Charles and see if we can work with Ehrin at Continental to get these other boxes resolved for you.
I'll forward this to Charles and see if we can work with Ehrin at Continental to get these other boxes resolved for you.
Also, spoiler alert for my DMS review....they are Friggin Awesome!
09-22-2016, 03:44 AM
#28
Rennlist Member
P.S. Ehrin said they had also seen these studs snap on 997 GT3. They believe head related.
I wonder what the toque spec of these nuts are? Im pretty sure Ehrin's boys follow the PAG manual here. If they were too tight then thats an issue for all. However if the nut is causing heat fatigue on the bolt then perhaps different materials need to be used?
I wonder what the toque spec of these nuts are? Im pretty sure Ehrin's boys follow the PAG manual here. If they were too tight then thats an issue for all. However if the nut is causing heat fatigue on the bolt then perhaps different materials need to be used?
09-22-2016, 08:00 AM
#29
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So there is no trick with the end studs on the mufflers, really I think it is just being smart about it. I have only broken 2 myself but have fixed about 20 easily. I can talk someone through it over the phone as well.
As as for preventing the studs to break
1) DO NOT USE AIR TOOLS
2) use some penetrant oil
3) wait until the muffler has cooled down
4) I do not fully remove the nuts.
Many this last one what I mean is I loosen the nut about 2 turns tops just enough to loosen the gasket and be able to slide the muffler out. Works every time.
As as for the tips nuts I make sure to spray those with a rost off ice which freezes the stud a little. Then the nuts spin off easy, Again only remove them when fully cold.
As as for preventing the studs to break
1) DO NOT USE AIR TOOLS
2) use some penetrant oil
3) wait until the muffler has cooled down
4) I do not fully remove the nuts.
Many this last one what I mean is I loosen the nut about 2 turns tops just enough to loosen the gasket and be able to slide the muffler out. Works every time.
As as for the tips nuts I make sure to spray those with a rost off ice which freezes the stud a little. Then the nuts spin off easy, Again only remove them when fully cold.
Last edited by Charles@dundonmotorsports; 09-22-2016 at 05:06 PM.
09-22-2016, 06:25 PM
#30
Nordschleife Master
Just to add to this topic. I replaced my third muffler with a SW bypass, boxed and stored my OEM. I was curious being I couldn't remember, but was pretty sure none of the studs had snapped when I removed the nuts. Looks like they are all in tact. What I did do was put some penetrant spray on the studs and the nuts came off fairly easy.